Mechanism for maintaining alignment between two relatively movable members

ABSTRACT

This disclosure relates to a mechanism for maintaining alignment between two relatively movable members, specifically platens or supports for retreading molds, although not limited thereto, and includes a pair of generally parallel screws .Iadd.having a common feed mechanism, the screws being fixed to the members against axial movement relative to each other .Iaddend.with .[.means for axially shifting.]. one of the screws .Iadd.being shiftable .Iaddend.relative to the .[.other.]. .Iadd.feed mechanism .Iaddend.to maintain alignment between the two platens or supports.

The present invention is directed to an apparatus for retreading tiresand includes a pair of relatively movable platens or supports carryingmatrices in which a tire is retreaded, the platens being moved relativeto each other by at least a pair of screws, and means being provided formaintaining alignment between the platens to assure that in the closedposition of the matrices there is relative perfect alignmenttherebetween.

A further object of this invention is to maintain the alignmentaforesaid by fixing a nut to one of the screws and providing means forimparting rotation to the nut thereby axially shifting the screw towhich the nut is affixed to maintain the desired alignment.

Still another object of this invention is to provide an apparatus of thetype heretofore set forth wherein the nut affixed to the screw isrotated by a plate embracing the same with the plate having an arcuateslot through which passes a bolt for maintaining a desired position ofrelative rotation between the plate and a fixed support.

With the above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following detailed description, the appended claimed subjectmatter, and the several views illustrated in the accompanying drawings.

IN THE DRAWINGS

FIG. 1 is a side elevational view of an apparatus for retreading tires,and illustrates one of a pair of screws for relatively moving a pair ofplatens carrying matrices defining in the closed position thereof a moldchamber in which a tire can be retreaded.

FIG. 2 is a fragmentary enlarged cross-sectional view taken generallyalong line 2--3 of FIG. 1, and illustrates a pair of screws forimparting relative motion between a pair of platens carrying matricesand means for axially shifting one of the screws relative to the other.

FIG. 3 is an enlarged fragmentary sectional view taken generally alongline 3--3 of FIG. 2, and illustrates the manner in which a nut is fixedto one of the screws for axially shifting the same.

FIG. 4 is a sectional view taken generally along line 4--4 of FIG. 3,and illustrates in more detail the manner in which the nut is rotated toshift the associated screw relative to the remaining screw.

FIG. 5 is a perspective view of a plate, and illustrates an aperture forembracing the nut and an arcuate slot permitting relative rotation ofthe plate and securement thereof to a stationary support.

A novel machine, apparatus or mechanism constructed in accordance withthis invention is illustrated in FIGS. 1 and 2 of the drawings, and isgenerally designed by the reference numeral 10. The apparatus 10includes a base 11 forming a support for a pair of screws 12, 13. Thescrews 12, 13 are disposed generally vertically and in parallelrelationship to each other. A lower threaded end portion 14, 15 of therespective screws 12, 13 passes through apertures (unnumbered) in thebase 11 and have threaded thereupon respective nuts 16, 17. A nut 18cooperates with the nut 17 to fasten the screw 13 to the base 11 andmeans, generally designated by the reference numeral 20 also fastens thescrew 12 securely to the base 11 but in keeping with this invention alsoperforms the function of permitting axial shifting motion of the screw12 relative to the screw 13 for alignment purposes in a manner to bedescribed more fully hereinafter.

Nuts 21, 22 having fixed thereto respective sprockets 23, 24 arethreaded upon the screws 12, 13, respectively and chains 25, 26 areentrained about the sprocket 23 and another sprocket 27, and about thesprocket 24 and another sprocket 28, respectively, with the sprockets27, 28 being keyed to a common shaft 30 driven by a motor 31. The motor31 is reversible in order that rotation may be imparted in oppositedirections to the nuts 21, 22 for the purpose of relatively moving aplaten or support 32 relative to another platen or support 33 fixed tothreaded upper end portions 34, 35 of the respective screws 12, 13 bynuts 36, 37 and 38, 39, respectively, in the manner clearly illustratedin FIG. 2.

The supports or platens 32, 33 carry matrix segments or molds 42, 43,respectively, which in the closed position thereof define an annularchamber C within which a tire (not shown) may be retreaded in aconventional manner as, for example, in the manner fully disclosed inApplicant's commonly assigned Application entitled AUTOMATIC PRODUCTIONMOLDS, Ser. No. 391,816 filed Aug. 27, 1973. The platens 32, 33 includeguide sleeves 44, 45, respectively, which telescopically receive guiderods 46, 47, respectively, fixed to respective bead aligner wheels 48,49 which are moved relative to each other by piston rods 51, 52,respectively, secured thereto and reciprocal in fluid or hydrauliccylinders 53, 54. The latter-noted application clearly discloses themanner in which the bead aligner wheels 48, 49 operate relative to atire (not shown) which is to be retreaded within the cavity C of theclosed matrices 42, 43.

Thus, upon rotation of the sprockets 27, 28 the nuts 21, 22 rotate andact through bearings (unnumbered) to lift or lower the platen 32relative to the platen 33 for opening and closing the matrices 42, 43.

Reference is now made specifically to FIGS. 3-5 of the drawings in whichthe means 20 is more specifically illustrated and includes a nut 60fixed by a pin 61 to the lower threaded end portion 14 of the screw 12.The nut 60 is embraced or surrounded by an aperture 62 of a plate 63which also includes an arcuate slot 64 and a handle 65. The dimension ofthe opening or aperture 62 is such as to act as a wrench for the nut 60,as is most readily apparent in FIG. 3. A bolt 66 passes through thearcuate slot 64 and is threaded into a threaded bore 67 of a cross piece68 of the frame 11. When the bolt 66 is loosened the handle 65 of theplate 63 can be rotated clockwise or counterclockwise and motion isimparted to the nut 60 which since keyed to the screw 12 will raise orlower the nut 21 relative to the nut 22 which in turn will raise orlower the left-hand end of the platen 32 relative to the right-hand end(as viewed in FIG. 2). Thus, should there be any misalignment betweenthe matrix segments 42, 43, particularly in the closed position thereof,such misalignment can be corrected by simply rotating the nut 60 bymotion imparted to the plate 63 with the same then being locked at adesired angular position of adjustment by tightening the bolt 66. Oncethus adjusted the platen 32 will move accurately into alignment with theplaten 33 when the matrices 42, 43 are closed, and should one or theother of the screws 12, 13 wear or cause misalignment then readjustmentof the platen 32 can again be made by simply rotating the nut 60 toraise or lower the nut 21 as the screw 12 rotates to thus raise or lowerthe platen 32.

While preferred forms and arrangement of parts have been shown inillustrating the invention, it is to be clearly understood that variouschanges in details and arrangement of parts may be made withoutdeparting from the scope and spirit of this disclosure.

I claim: .[.1. A mechanism for maintaining alignment between tworelatively movable members comprising a pair of relatively movablemembers, a pair of screw means for moving said members relative to eachother, and means for axially shifting said pair of screw means relativeto each other whereby misalignment between said members can be readilycompensated..].
 2. The mechanism as defined in claim .[.1.]. .Iadd.17.Iaddend.wherein said pair of screw means are in generally parallelrelationship to each other.
 3. The mechanism as defined in claim .[.1.]..Iadd.17 .Iaddend.wherein said relatively movable members carrycooperative means for defining a mold which is closed when saidrelatively movable members are adjacent each other. .[.4. The mechanismas defined in claim 1 including means rotatably carried by said pair ofscrew means for moving said movable members relative to each other..]..[.5. The mechanism as defined in claim 1 including means rotatablycarried by said pair of screw means and movable in unison therealong formoving said movable members relative to each other..].
 6. The mechanismas defined in claim .[.1.]. .Iadd.17 .Iaddend.wherein said axiallyshifting means is a nut carried by .Iadd.said .Iaddend.one of said pairof screw means.
 7. The mechanism as defined in claim .[.1.]. .Iadd.17.Iaddend.wherein said axially shifting means is a nut fixedly carried by.Iadd.said .Iaddend.one of said pair of screw means.
 8. The mechanism asdefined in claim .[.1.]. .Iadd.17 .Iaddend.including a stationarysupport, and said axially shifting means .[.axially.]..Iadd.rotationally .Iaddend.shifts .[.at least.]. .Iadd.said.Iaddend.one of said pair of screw means relative to said stationarysupport.
 9. The mechanism as defined in claim 8 wherein said pair ofscrew means are in generally parallel relationship to each other.
 0. Themechanism as defined in claim 9 wherein said axially shifting means is anut carried by one of said pair of screw means.
 11. The mechanism asdefined in claim 10 including means for securing said nut to saidstationary support.
 12. The mechanism as defined in claim 10 includingmeans for adjustably securing said nut to said stationary support. 13.The mechanism as defined in claim 11 wherein said securing means is aplate member secured to said nut, and means for angularly adjustablysecuring said plate to said stationary support.
 14. The mechanism asdefined in claim 12 wherein said securing means is a plate membersecured to said nut, and means for angularly adjustably securing saidplate to said stationary support.
 15. The mechanism as defined in claim13 wherein said securing means is an aperture in said plate defined byan edge embracing said nut.
 16. The mechanism as defined in claim 14wherein said securing means is an aperture in said plate defined by anedge embracing said nut. .Iadd.
 17. A mechanism comprising a pair ofrelatively movable members, a pair of screw means extending between andconnected to said members for moving said members relative to eachother, means fixing said screw means against axial movement relative toone of said members, feed means carried by said screw means foractuation in unison to effect movement of the other of said membersbetween parallel positions, and means for axially shifting one only ofsaid screw means relative to its respective feed means for varying theangular relationship between said members, while said one screw meansremains fixed against axial movement. .Iaddend..Iadd.
 18. The mechanismas defined in claim 17 wherein said means fixing said screw meansagainst axial movement relative to said one member includes meansmounting said one screw means for rotation relative to said one member..Iaddend..Iadd.
 19. The mechanism of claim 18 together with meansconnected to said one screw means for changing and fixing said one screwmeans rotationally about its axis. .Iaddend.